Magic is a medical alert assistance dog, and has been trained to detect a minute shift in the blood sugar levels of his owner, Claire Pesterfield.

Using his superior sense of smell, he is capable of detecting tiny odour concentrations - around one part per trillion.

Without Magic's assistance, changes in her blood sugar levels could put her at risk of a seizure, or - in extreme cases - the onset of a coma.

Claire has type 1 diabetes, but - unlike most people with the condition - her body does not display the warning signs that a dangerous episode might be about to occur.

Infected cells

NHS trials are currently assessing if dogs could also be used to detect prostate cancer.

The research being conducted offers an opportunity for the disease to be detected at an early stage - vital for improving survival rates.

The dogs - usually from the gundog breed, such as labradors and springer spaniels - are taught to detect a sample of urine from a patient with prostate cancer.

It is thought that the dogs can pick up the odour of cancer "volatiles", which travel from the infected cells into the urine as the body tries to dispose of the chemicals.

England's Health Secretary Jeremy Hunt told him he will consider the findings of the NHS trial when published.

"I think ideas like this sometimes don't get looked at as quickly as they should, because they sometimes get put in the quackery box.

"I will personally look at this research when it comes through. One of our jobs as MPs is to question orthodoxies and look at different ways of doing things that possibly the establishment has swept under the carpet.